First off, I just swapped out a standard dual downpipe combination manifold for my stock cross-over secondary butterfly manifold. It took some time to drill out the old broken exhaust studs and put in new ones, but the installation went perfect and I was able to knock out an old mud-dauber nest up under the intake. Yeah for me... what does this have to do with JB weld and SU potmetal?

I failed to mention that while cleaning my HS6s last night, I managed to break part of my forward carb float chamber cap. The cap has a hingepin for the float pressed through two loops in the potmetal. I've disassembled SU floats many times before, but this time I did something wrong and broke one of those hingepin loops. It looked like there was a crack and it was discolored on the broken surfaces so I think I just pushed a bad piece over the edge.

Not having a precise replacement spare cap (save from the pair on my 67 wagon) I cleaned the broken surface gently with a brush and some Gumout and then whipped up a little JB weld. I dabbed a bit on the broken surfaces and pressed them togther until they stuck. I could not wait overnight for it to cure, so an hour or so later, I put the float back together and reassembled the carbs.

I have no idea how long this will hold, but I was quite amazed to find that the part looked perfect and undamaged when I checked it today for my manifold swap.
I had to really squint to see the crack and the whole cap feels solid. I did not whack it to really test it, nor try to disassemble the float again, but it seems to be holding up ok.

So... have any of you tried to repair SU potmetal with JB Weld before? If so, how well did it hold up and for how long?

My previous experiences with this stuff have been very good. I've used it to seal leaking gas tanks (including my new, used sedan tank), fix a broken plastic tank volvo radiator, seal my bathroom drain plumbing, and many other similar repairs. I also used it as a filler on an ovaled exhaust stud hole in my new (old) manifold earlier this evening - so I hope that fix holds up too...

I have seen this stuff break under repeated impact stress and in cases of dissimilar materials (glass glued to steel), but I'm hoping that I can avoid replacing the top cap of my float chamber for a long time.

Any thoughts?